Department of Hydrobiology, Faculty of Biology, University of Białystok, Ciołkowskiego 1J, 15-245, Białystok, Poland.
Department of Zoology and Genetics, Faculty of Biology, University of Białystok, Ciołkowskiego 1J, 15-245, Białystok, Poland.
Sci Rep. 2021 Nov 30;11(1):23158. doi: 10.1038/s41598-021-02648-7.
The taxonomic status of the genus Bythotrephes Leydig (Crustacea: Cladocera) has been debated since the second half of the XIX century. The most widespread view of recent decades has been that Bythotrephes is a monotypic genus, which was support by preliminary molecular data. However, the recent detailed morphological revision of this genus clearly distinguishes at least seven species. Therefore, we performed a multi-lake survey in Central Europe to give new insight into the taxonomic status of Bythotrephes by combining genetic analysis with traditional morphology-based taxonomy. Based on the morphology we identified two species in Central Europe, B. brevimanus and B. lilljeborgi, as well as hybrid forms. For the genetic analysis, we used newly obtained 113 sequences of mtDNA COI gene of the 535-bp length Bythotrephes from Central Europe and sequences downloaded from GenBank. There were no significant differences between all analyzed sequences, which supports the hypothesis that Bythotrephes is a monotypic genus, with only one highly polymorphic species. On the other hand, the results of our work could point out that the COI gene is insufficient to evaluate the taxonomic status of Bythotrephes. Nonetheless, we have identified 29 new haplotypes of mtDNA COI, and one which was the same as the haplotype found in North America and Finland. Furthermore, this haplotype was the source variant from which most other haplotypes were derived.
自 19 世纪下半叶以来，关于 Bythotrephes Leydig（甲壳纲：枝角目）属的分类地位一直存在争议。近几十年来最广泛的观点是，Bythotrephes 是一个单种属，这一观点得到了初步分子数据的支持。然而，最近对该属的详细形态修订清楚地区分了至少 7 个物种。因此，我们在中欧进行了多湖调查，通过将遗传分析与传统形态分类学相结合，对 Bythotrephes 的分类地位进行了新的探讨。根据形态学，我们在中欧识别出了两个物种，B. brevimanus 和 B. lilljeborgi，以及杂交形式。对于遗传分析，我们使用了从中欧获得的长度为 535bp 的 mtDNA COI 基因的 113 个新序列和从 GenBank 下载的序列。所有分析的序列之间没有显著差异，这支持了 Bythotrephes 是一个单种属的假说，只有一个高度多态的物种。另一方面，我们工作的结果可能表明 COI 基因不足以评估 Bythotrephes 的分类地位。尽管如此，我们已经确定了 mtDNA COI 的 29 个新的单倍型，其中一个与在北美和芬兰发现的单倍型相同。此外，该单倍型是大多数其他单倍型的起源变体。
